private void bgwk_keepsession_DoWork(object sender, DoWorkEventArgs e)
 {
     while (true)
     {
         try
         {
             if (!bf.Ping())
             {
                 return;
             }
         }
         catch (BeanfunIsBusyException)
         {
             Thread.Sleep(1000);
             continue;
         }
         Thread.Sleep(60000);
     }
 }